Grab



March 31, 1925.

GRAB

Filed Feb. 18, 1924 W. H. NICHOLSON INVEN TOR. mil-Nicholson Patented Mar. 31, 1925.

WILLIAM H. NICHOLSON, or TAIFT, CALIFORNIA,

GRAB.

Applicationfiled February is, 1924.. Serial n 693,652.

To all whom it may concern."

Be it known that I, WILLIAM H. NICHOL- soN,.a citizen of the United States, residing at Taft, county of Kern, State of California, have invented certain new and useful Improvements in Grabs; and I do declare the following to be a full, clear, and exact clescription of the same, reference being-had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this application. I

This invention relates to improvements in that class of devices known as fishing tools, used in connection with well drilling operations, and particularly to'that type of fishing tool commonly known as a grab, used particularly to catch and grasp broken-fishtail bits and similar articles lost in the well. I

The principal object of my invention is to provide a tool of this character so constructed that the article being fished for will be automatically engaged and grasped with a grip whose holding force increases with an increase of resisting pressure thereagainst. 7

Another obj ect'is to arrange or mount the actual grabs or gripping members in such a manner that with any spread or contraction they move parallel to each other, so that a flat surface being gripped is engaged over the full length of the grabs with equal force.

A further object is to mount the grabs in such a manner that no interference with a free flow of flushing water to a point beparts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of ref erence indicate corresponding parts in the several views:

Fig. 1 is an exterior side elevation of the device. 1

Fig. 2 is a front elevation of the same,

half in section.

Figs. 3 and 4 are cross sections on the lines This head is formed with a downwardly extending Wedge or V shaped member 5,

symmetrically disposed relative to the lon-' gitudinal axis of the tool. The-opposite side faces of the member.

are provided'with guide ribsor projections 6 located adjacent and parallel to the sloping edges. of said. member, which serve as guides and supports for the grooved heads 7 of the grabs 8.

These grabs are rigid members depending below the member 5 a certain distance: and having oppositely and transversely disposed teeth 9 cut in their adjacent faces in vertical and transverse parallel alinement, the upper faces of the teeth lying in substantially horizontal'planes. From the lowermost of the teeth, to the lower extremity of the grabs, the adjacent faces of the latter are cut with a diverging flare or slope as at 10.

The grabs are normally heldadjacent the lower end of the headmemberfi, and'forced to move at all times in unison, by means of a crosshead 11 resting on the grab-heads 7. This crosshead is vertically slidable in a transverse slot'12 cut inthe head 4 and ex: tending down into the member 5 for a certain distance.

Fixed on the crosshead l1 centrally thereof and projecting thereabove is a stem 13, slidable in a suitablerecess 14: provided in the head 4, a spring 15 mounted in the shank 1 above the stem bearing down thereon. The

stem is of suflicient' length so that it forms a'good guide and bearing member for the orosshead, positively preventing any lateral Of thelattgn v v The shanks, stem and member 5 are axially drilled throughout their entire length as at 16 to provide an unobstructed'water passage from one end of the tool to the other.

Various methods of construction of the members 4 and 5, and mounting of the grabs 8 on the latter, may be employed to enable the grabs to be assembled and removed when necessary. In the present case, I have shown the guide members 6 on the wedge member 5 as terminating short of the lower end thereof to enable the grab-heads 7 to be individually slid down and off their supporting piece and clear the latter of all sand, mud,

etc, in which it may have been buried.

I A sharp downward thrust is then given to the tool causing the grabs to-be spread apart and the broken piece to passup therebetween. Since the opposite guide ribs 6 of the wedge shaped member'are symmetrically disposed relative to the axis of the tool, the grabs must move so as to maintain their parallel alinement relative to each other-and to a vertical plane. Also on account of the slidable but rigidly supported' crosshead 11, one grab cannot move without the other, and therefore both grabs will move to the-same extent.

A flat piece being forced up between the grabs will therefore be engaged on its opposite sides and throughout its height and width by the teeth 9, insuring a rigidgrip on the piece.

Then when the tool is ra'ised, th'e grabs, owing to the converging guides on which they are mounted and to the spring 15 acting through the crosshead 11 to force the grabs downwardly,w-ill automatically tend to move toward each other and into firm gripping engagement with the piece therebetween.

There being no connecting member between the grabs below the member 5, there is nothing to obstruct thefio'w of water from the bore 16 and interfere with a good flushing action. I

From the foregoing description it will be readily seen that I have produced such a device as substantially, fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the presentand preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form grabs depending from said V shaped memher and 'mounted thereon for sliding movebent in planes parallel to the side edges of the V shaped member.

2. A fishing tool comprising a shank, a V shaped member at the lower end thereof and depending therebelow, and opposed grabs depending from said V shaped memher and mounted thereon for sliding movement in, planes parallel to the side edges of the V shaped member, and means whereby said grabs when acted on will move in unison and to thesame extent.

3LA fishing tool comprising 'a shank, a V shaped member at the lower end thereof and depending therebelow, and opposed grabs depending from said V shaped member and mounted thereon for sliding movement in planes parallel to the side edges of the V shaped member, and a crosshead bearing on top of thelgrabs and slidably mounted for vertical movement in the shank.

4. A fi'shing toolcom-prisi-ng a shank, opposed and separate grabs depending from the lower end thereof, and guide and supporting means for the upper ends of said grabs disposed therebetween and depending from the shank, there being an unobstructed opening between 'thegrabs from the lower end of the supporting means downwardly.

5.=A fishing tool comprising-a shank, opposed grabs depending from the lower end thereof, and guideandsuppo'rting means for the uppere'nds of said grabs disposed therebetween and depending. from the shank, said guide means being arranged to allow the i grabs to move up and down in diverging and converging relation respectively while maintaining a parallel relationship to each other. 6. A 'fishing'tool comprisinga shank, a V

shaped member'at the lower end thereof and depending therebelow, and opposed grabs depending from and both supported and guided by said; member for upward diverging and downward converging movement.

7. A fishing tool comprising a shank, a -V shaped member-at the lower end thereof and depending therebelow, and opposed grabs depending from and guided by said member, for upward diverging and downward converging movement, while maintaining the grabs in arallel relationship to each other.

8. A e; grabs mounted at and'depending from the lower end thereof and arranged for limited vertical-movement, means whereby when the grabs are moved upwardly they will autohing' tool comprising a shank,

mounted for vertical movement in the shank,

and spring means in the shank acting to cause a downward pressure on the crosshead. 9. A structure as in clann 8, 1n which the shank, grab-movement controlling means, and crosshead are provided with vertical 10 passage means therethrough, whereby to allow of an unobstructed flow of water from one end of the tool tothe other.

In testimony whereof I alfix my signature.

WILLIAM 1-1. NICHOLSON. 

